NOTES. CXX1 



of the services of Her Majesty's ships arid vessels employed in Hydrographies! 

 Surveys, by directing that determinations of the three magnetic elements should 

 be made by them at the several ports and harbours which they may visit, as 

 well as at sea daily, as often as the weather permits, in their passages from, 

 port to port. Such determinations have been executed, in whole or in part, 

 by the surveying expeditions of Sir Edward Belcher (1837 1840, and 1843 

 1 84 7) to the north-west coast of America, the islands of the Pacific, and the Indian 

 and Chinese seas ; of Captain Sullivan (18381839) to the Falkland Islands ; 

 of Captain Allen (18411842) to the western coast of Africa; of Captain 

 Blackwood (18421846) to Australia and Torres Strait ; of Captain Barnett 

 (184318 *) to Bermuda and the West Indies; of Captain Kellett 

 (184518 *) to the Pacific; of the Arctic Expedition under Sir John 

 Franklin (184518 *) ; of Captain Stanley (184718 *) to Australia 

 and New Guinea ; of Captain Moore (184818 *) to Kamptschatka and 

 Behring's Strait; and of Captain Stokes (184818 *) to New Zealand. 

 To these should bo added, as a special undertaking at the expense of the East 

 India Company, a magnetic survey of the islands of the Indian Archipelago, 

 by Lieut. Elliot, of the Madras Engineers, commenced in 1846, and still in 

 progress. When it is remembered that several of the above-named surveys 

 include periods of three or four years, and in some instances not only deter- 

 minations at the several ports and harbours which may have been visited, but 

 also daily observations, weather permitting, of the three magnetic elements at 

 sea in passages from port to port, the accumulation of materials, and their 

 already extensive distribution over the surface of the globe, may in some 

 degree be judged of. These surveys, with others which may be expected to 

 be made under the present favourable disposition of Her Majesty's Govern- 

 meut towards scientific researches, and, taken in conjunction with extensive 

 magnetic surveys which are in progress on the continent of Europe (particu- 

 larly in the Austrian dominions), give a full promise of the speedy realisation 

 of M. de Humboldt's wish so earnestly expressed, that the materials of the 

 first general magnetic map of the globe should be assembled, and even permit 

 the anticipation, that the first normal epoch of such a map will be but little 

 removed from the year 1850.] 



( 515 ) p. 335. On the oldest thermometers, see Nelli, Vita e Commercio 

 liuerario di Galilei (Losanna, 1793), Vol. i. p. 6894; Opere di Galilei 

 (Padovo, 1744), T. i. p. lv. ; Libri, Histoire des Sciences mathematiques eu 



* When the concluding date is not filled up, the observations are still in prosrea*. 



